Increasing demand for more powerful and convenient data and information communication has resulted in the proliferation of a number of wireless communication technologies. Within the field of wireless communications, a number of industry standards and operational protocols have been developed to address the interoperability of disparate devices and equipment within a single wireless network. Many such standards and protocols provide for basic communication amongst network components regarding device configuration and operation. Commonly, such communication is provided in the form of one or more messages passed between components during the course of system operation.
Consider, for example, the general architecture and operation of a wireless Radio Access Network (RAN), such as a wireless RAN based upon a CDMA2000 standard (a registered trademark of the Telecommunications Industry Association, TIA-USA). Commonly within such a RAN, a Packet Data Serving Node (PDSN) is connected to one or more Packet Control Functions (PCFs). A messaging interface is provided between a PDSN and its associated PCFs for communicating operational information. Each PCF may be connected to a number of base stations (BSs), each of which—in turn—may be operatively coupled to a number of mobile stations (MSs). Various messaging interfaces may be provided between PCF and BS, as well between BS and MS.
In a typical operational scenario for such a system, an MS will establish a packet data session (PDS) on a particular BS, which will establish interface connections with its associated PCF for that session. That PCF, in turn, establishes connections with its associated PDSN. Each PCF controls several BSs, or other access points, and the footprint of combined coverage areas of these BSs makes up a packet data zone (PDZ) controlled by that PCF. Each PCF thus functions as a PDZ control component.
When—due to inactivity by the MS user—a PDS goes dormant, its BS drops traffic channel to the MS to preserve radio resources, and also removes an associated interface connection to the PCF. Before removing this interface connection to the PCF, the BS communicates session state information for the MS, which is then stored in the PCF. This is done so that when that MS re-activates the dormant PDS, the BS can simply retrieve the session information from the PCF, rather than the MS—resulting in faster PDS re-activation times.
Commonly, an MS may move to a new PDZ while in a dormant state. Each BS within a given PDZ broadcasts a Packet Zone Identifier (PZID), along with a System Identifier (SID) and Network Identifier (NID), on an overhead channel. When an MS recognizes such a signal from a new BS—indicating that it has crossed over to a new PDZ—it sends an Origination Message to the new BS. That BS then alerts its PCF of the presence of a new, dormant PDS, and that PCF attempts to contact the PDSN, which is connected to the previous PCF, so as to establish a new connection in case data arrives at the PDSN for the MS. The PCF does so using a standardized selection algorithm that is based on the MS's International Mobile Subscriber Identity (IMSI).
Unfortunately, conventional systems do not appear to allow a new host PCF to retrieve stored session information from a previous host PCF. This leads to delay in re-activating a PDS for the MS—especially where certain operational parameters (e.g., quality-of-service) need to be re-negotiated. In addition, if the new host PCF was not able to contact the previous host PDSN and therefore had to set up a connection with a new PDSN, a previous host PCF has no way of knowing how long to store session information for a dormant mobile. It may be possible that a given MS simply remains dormant, or that the MS has moved on to a new PDZ. Consequently, session information may be maintained on a previous host PCF indefinitely—unnecessarily consuming system resources.
As a result, there is a need for a system that provides structures and methods by which operators can configure networks to allow a new PCF, using MS-related information it receives from one of its BSs, to contact an old PCF to retrieve session information for a given MS—and by which an old PCF may discard unneeded session information after retrieval by another PCF—providing reliable, high performance wireless communications in an easy and efficient manner.